Sorry for being absent from the forum for so long.
I have an ancient pendrive that still works well, but is irresponsive to `pcmanfm→side pane→Right Clk→Eject Removable Media` . It has an LED lamp that keeps glowing even when "Eject..." is clicked.
I have had the solution for a long time. I had found it from elsewhere then also from here: Ask Ubuntu 447471
and here: Karl's Code
I first run :

Code:

for device in $(ls /sys/bus/usb/devices/*/product); do echo $device;cat $device;done

I identify the Mass Storage Device, then use the command:

Code:

echo 'x-y' | sudo tee /sys/bus/usb/drivers/usb/unbind

and the LED switches off, which is an evidence that the drive is powered off.
One could also have used:

Code:

dmesg | grep -e "Mass Storage"

then use the `unbind` code.
Is there a possibility of adding these two lines of codes as script in `pcmanfm→side pane→Right Clk→Eject Removable Media`?

I will also write to pcmanfm user-group for a solution and will post the responses, if any, here too. I still use Knoppix 7.2.0